Art comes in many different forms, but one that people don't often think about is concert poster art.

The genre dates to '50s rock 'n' roll — one can easily Google a classic Chuck Berry concert poster. In the '60s, artistic promotions for shows at San Francisco's famed Fillmore rose in popularity. The Seattle grunge scene brought a resurgence of concert posters in the '90s.

Websites such as gigposters.com and the American Poster Institute and its poster art show, Flatstock, helped further the movement.

A sampling of old and new concert posters can be found at the ongoing POSTGIG exhibit going on now at the University of Missouri-St. Louis.

"It's pretty cool stuff," says exhibit curator Clifford Stoltze, founder of Boston-based Stoltze Design and author of "1000 Music Graphics" (2008), which that looks at posters, packaging and websites.

"The shows have been in a few other cities after I initially put it up in Boston, and without my marketing it, people have been asking for it," Stoltze says.

About 20 concert-poster artists and studios are represented at POSTGIG. Nearly 120 posters will be displayed, including show posters for Sonic Youth, Neko Case, the Decemberists, Yonder Mountain String Band, Feist, the Shins and Lyle Lovett. Many of the posters come from Stoltze's collection.

"I have a couple hundred posters, and more than half of them are in this show," he says. "I have other posters I don't want to travel. I put this show together thinking I have this drawer full of posters, but they seem muzzled. I want people to see them."

Stoltze says the posters in the exhibit represent a nice use of graphic elements, typography and printing techniques. Some of the posters are busy and layered; others are more minimal. And all of them are what would be considered "legitimate."

Apparently, not all concert posters are created equally.

"To be legitimate, there has to be a client there," he says. "It has to be made to promote a concert or a venue, on behalf of the band or the venue, not just a personal project. Anybody can say, 'I like this band, and I'm going to do a poster.' But if there is no connection to the band or artist or venue, it's just a personal art project."